This invention relates to an antenna provided to a vehicle rear window glass for receiving FM radio and television (TV) broadcast waves, the antenna being constructed of conductive strips attached to the window glass by using a space above defogging heater strips. The antenna is particularly suited to automobiles.
In recent automobiles there is a trend to the adoption of a so-called window glass antenna for receiving radio broadcast waves, and there is an increasing demand for a window glass antenna which can efficiently receive both FM radio broadcast waves and TV broadcast waves. To meet such a demand there are several proposals.
For example, JP 61-203702 A proposes a windshield antenna having, as an essential element, a conductive strip which extends vertically in the central region of the windshield, and JP 61-121603 A proposes a rear window glass antenna which is arranged in a space left above an array of defogging heater strips and includes two feed points which are connected to two different points of an antenna element, respectively.
However, in the case of providing an antenna in a central region of the windshield the driver's field of view is inevitably obstructed.
In the case of providing an antenna to an automobile rear window glass which needs to be provided with defogging heater strips, the antenna must be arranged in a relatively narrow space contiguous to an edge of the window glass since a central region is occupied by the heater strips. That is, the antenna nears the metal body of the car which is regarded as the ground. By reason that the allowed space is narrow and off-centered it is difficult to construct an antenna which exhibits high reception gain over a wide range of frequency including the FM radio broadcasting bands and both the VHF and UHF bands for TV broadcasting.